GB539117A - Improvements in or relating to aircraft controls - Google Patents

Abstract

539,117. Controlling aircraft. TAMPIER, R. J. C. Feb. 28, 1940. No. 3653. [Class 4] [Also in Group XXX] An auxiliary aerofoil normally nested beneath the leading or trailing edge of a main wing but movable so as to be clear of the wing, is completely supported on one or more racks slidably mounted in guides in the main wing structure, the racks being geared to pinions by which the aerofoil may be extended and retracted. The aerofoil is tiltable relatively to the rack or racks when in the extended position. Fig. 9 shows a wing section in which an auxiliary aerofoil 16 is normally nested beneath the leading edge to complete the contour of the wing. The aerofoil is pivoted to racks 20, 21, one at each end of the aerofoil by which the aerofoil is projected and retracted. The aerofoil may be tilted as shown after or during its projection. Fig. 1 shows an aeroplane wing having two such aerofoils 16 17 at its forward edge and two additional aerofoils 18, 19 at the wing tips, the latter being movable in opposite directions by a hand-wheel 54' selectively clutchable to the operating gear for the aerofoils and the ailerons. The auxiliary aerofoils are each carried on two racks 20, 21, the outer ends of the racks being connected by a spar which carries two irreversible hinges 24 of the kind described in Specification 496,875. The hinges are controlled by racks 25, Fig. 2, linked as shown to a rack 40 engaging a pinion 41 having a dog clutch on each side of it. The pinion can be moved by linkage from the cockpit to connect it to either of two pinions 28, 43, the former engaging the rack 20. The pinion 43 engages a rack 48 connected by linkwork to a rack 52 engaged by a pinion rotated by a hand-wheel 54. The end aerofoils 18, 19 are tilted, but in opposite directions by connections to a handwheel 54<1> which at high speeds of the aircraft may be declutched from the aerofoil mechanism and used only for operating the ailerons. Alternatively a separate hand wheel may actuate the ailerons. The racks 20, 21 engage pinions 28, 29 on shafts 30, the two shafts on each wing being connected by bevel gears 31, 32. Each shaft 30 is movable by an electric motor 3 or it may be moved by hand. In their extended positions the racks 20, 21 are locked by levers 2 actuated from the cockpit. By clutching the pinion 41 to the pinion 43 during the extension of the racks 20, 21, the racks 48 being held stationary the aerofoils may be tilted as they are projected. Only one of the two hinges of each aerofoil need be irreversible or hinges similar to those described in Specification 499,503 may be used. A rear aerofoil normally nested beneath the trailing edge of the wing and actuated by similar mechanism also is described. The aerofoils 16, 17 may be tilted in opposite directions for lateral balancing. Fig. 11 shows a modification in which the aerofoils are triangular, the spar 23 of each aerofoil being pivoted about a vertical pivot 70 and connected by a short link 71 to the rack 20. The aerofoil is tiltable on the spar 23 by the controllable hinges 24.